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Poitras I, Campeau-Lecours A, Mercier C. Relationship between somatosensory and visuo-perceptual impairments and motor functions in adults with hemiparetic cerebral palsy. Front Neurol 2024; 15:1425124. [PMID: 39087017 PMCID: PMC11290339 DOI: 10.3389/fneur.2024.1425124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Accepted: 07/01/2024] [Indexed: 08/02/2024] Open
Abstract
Introduction Children with cerebral palsy (CP) exhibit a variety of sensory impairments that can interfere with motor performance, but how these impairments persist into adulthood needs further investigation. The objective of this study was to describe the sensory impairments in adults having CP and how they relate to motor impairments. Methods Nineteen adults having CP performed a set of robotic and clinical assessments. These assessments were targeting different sensory functions and motor functions (bilateral and unilateral tasks). Frequency of each type of impairments was determined by comparing individual results to normative data. Association between the sensory and motor impairments was assessed with Spearman correlation coefficient. Results Impairment in stereognosis was the most frequent, affecting 57.9% of participants. Although less frequently impaired (26.3%), tactile discrimination was associated with all the motor tasks (unilateral and bilateral, either robotic or clinical). Performance in robotic motor assessments was more frequently associated with sensory impairments than with clinical assessments. Finally, sensory impairments were not more closely associated with bilateral tasks than with unilateral tasks. Discussion Somatosensory and visuo-perceptual impairments are frequent among adults with CP, with 84.2% showing impairments in at least one sensory function. These sensory impairments show a moderate association with motor impairments.
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Affiliation(s)
- Isabelle Poitras
- Center for Interdisciplinary Research in Rehabilitation and Social Integration, CIUSSS de la Capitale-Nationale, Quebec City, QC, Canada
- School of Rehabilitation Sciences, Laval University, Quebec City, QC, Canada
| | - Alexandre Campeau-Lecours
- Center for Interdisciplinary Research in Rehabilitation and Social Integration, CIUSSS de la Capitale-Nationale, Quebec City, QC, Canada
- Department of Mechanical Engineering, Laval University, Quebec City, QC, Canada
| | - Catherine Mercier
- Center for Interdisciplinary Research in Rehabilitation and Social Integration, CIUSSS de la Capitale-Nationale, Quebec City, QC, Canada
- Department of Mechanical Engineering, Laval University, Quebec City, QC, Canada
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Sakurai M, Spitzley KA, Karduna AR. Awareness of Visual Offset Reduces but Does Not Eliminate Joint Repositioning Errors in Virtual Reality. J Mot Behav 2024; 56:592-599. [PMID: 39014967 DOI: 10.1080/00222895.2024.2368120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 05/16/2024] [Accepted: 06/07/2024] [Indexed: 07/18/2024]
Abstract
The present study investigated the effect of visual offset (visuo-proprioceptive mismatch) in joint repositioning task in a three-dimensional virtual reality (VR) environment when participants were instructed to ignore vision. Twenty-five physically healthy young individuals performed shoulder joint position sense test. Repositioning accuracy was tested under two visual conditions, accurate and offset visions, and two instructions, no guidance or ignore vision. In accurate vision trials, the virtual hand of the tested limb seen in VR was congruent with where the participant placed their hand. In the offset vision condition, the virtual hand was seen 8° above or below their actual hand in the vertical plane. Repositioning error (i.e. constant error) in offset vision trials was lower when the participants were instructed to ignore vision compared to when no instruction about the visual offset was given (p < 0.001). However, constant error in offset vision trials was larger than accurate vision trials when the participants tried to ignore vision in both visual conditions (p < 0.001). Our results suggest that humans may be able to down-weight vision to some extent by conscious effort, while the influence of vision is difficult to eliminate when vision is present.
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Affiliation(s)
- Motoki Sakurai
- Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
| | - Kate A Spitzley
- Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
- Slocum Research and Education Foundation, Eugene, Oregon, USA
| | - Andrew R Karduna
- Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
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Celicanin M, Harrison AP, Kvistgaard Olsen J, Korbo L, Løkkegård A, Danneskiold-Samsøe B, Siebner HR, Ilic TV, Bartels EM. Probing motor dynamics at the muscle level-Acoustic myography in Parkinson's disease. Physiol Rep 2023; 11:e15631. [PMID: 36945885 PMCID: PMC10031214 DOI: 10.14814/phy2.15631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 02/09/2023] [Accepted: 02/13/2023] [Indexed: 03/23/2023] Open
Abstract
Acoustic myography (AMG) noninvasively probes muscle activity. We explored whether AMG captures abnormal motor activity in patients with Parkinson's disease (PD) and how this activity is modulated by antiparkinsonian medication. Twenty patients with PD underwent AMG of the biceps, triceps, extensor carpi radialis longus, and adductor policis muscles of the more affected arm during active and passive movements, using a mobile AMG device (CURO, Denmark). AMG and assessment of motor symptoms were performed in a pragmatic off-medication state, as well as one and 3 h after oral intake of 200 mg levodopa. Three AMG parameters were calculated using the CURO analysis system. Motor efficiency was expressed by the E-score, muscle fiber recruitment by the temporal T-score, spatial summation by the S-score, and S/T ratio. Twenty age- and sex-matched healthy subjects served as controls. Group mean values were statistically compared using unpaired two-tailed adjusted t-test and ANOVA with Tukey´s correction for multiple comparison (p ≤ 0.05). For the biceps and extensor carpi radialis longus muscles, the active movement S:T ratio was lower in PD relative to healthy controls. The E-score was also lower during active and passive flexion/extension movements in the off-medication state. No significant between-group differences in the AMG scores were noted for the triceps muscle during active or passive movements. The active S:T ratio and the E-score during active elbow flexion and extension may offer a useful means to quickly assess abnormal motor activity and the effect of drug treatment in PD.
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Affiliation(s)
- M Celicanin
- Department of Neurology, Copenhagen University Hospital, Bispebjerg and Frederiksberg, Copenhagen, Denmark
- The Parker Institute, Copenhagen University Hospital, Bispebjerg and Frederiksberg, Frederiksberg, Denmark
| | - A P Harrison
- University of Copenhagen, PAS (Physiology), Faculty of Health and Medical Sciences, Kobenhavn, Denmark
| | - J Kvistgaard Olsen
- The Parker Institute, Copenhagen University Hospital, Bispebjerg and Frederiksberg, Frederiksberg, Denmark
| | - L Korbo
- Department of Neurology, Copenhagen University Hospital, Bispebjerg and Frederiksberg, Copenhagen, Denmark
| | - A Løkkegård
- Department of Neurology, Copenhagen University Hospital, Bispebjerg and Frederiksberg, Copenhagen, Denmark
| | - B Danneskiold-Samsøe
- The Parker Institute, Copenhagen University Hospital, Bispebjerg and Frederiksberg, Frederiksberg, Denmark
| | - H R Siebner
- Department of Neurology, Copenhagen University Hospital, Bispebjerg and Frederiksberg, Copenhagen, Denmark
- University of Copenhagen, PAS (Physiology), Faculty of Health and Medical Sciences, Kobenhavn, Denmark
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Hvidovre, Denmark
| | - T V Ilic
- Department of Neurophysiology, Medical Faculty of Military Medical Academy, University of Defense, Belgrade, Serbia
| | - E M Bartels
- Department of Neurology, Copenhagen University Hospital, Bispebjerg and Frederiksberg, Copenhagen, Denmark
- The Parker Institute, Copenhagen University Hospital, Bispebjerg and Frederiksberg, Frederiksberg, Denmark
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Relationship between Cervicocephalic Kinesthetic Sensibility Measured during Dynamic Unpredictable Head Movements and Eye Movement Control or Postural Balance in Neck Pain Patients. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19148405. [PMID: 35886255 PMCID: PMC9317579 DOI: 10.3390/ijerph19148405] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 07/05/2022] [Accepted: 07/07/2022] [Indexed: 01/27/2023]
Abstract
Cervical afferent input is believed to affect postural balance and oculomotor control in neck pain patients, but its relationship to cervicocephalic kinesthesia, describing movement sense, has not yet been studied. The aim of this study was to analyze the relationship of two aspects of cervicocephalic kinesthesia to postural balance and oculomotor control in neck torsion positions. Forty-three idiopathic neck pain patients referred from orthopedic outpatient clinics and forty-two asymptomatic controls were enrolled in the study. A force plate was used to measure center-of-pressure movements during parallel stances under neutral and neck torsion maneuvers. Video-oculography was used to assess eye movements during smooth pursuit neck torsion test (SPNTT), while kinesthetic awareness was measured using the Butterfly test and head-to-neutral relocation test. Multiple regression was used to describe relationships between tests. Body sway in the anterior-posterior direction was related to Butterfly parameters but less to the head-to-neutral test. A medium relationship between Butterfly parameters and gain during SPNTT, with less SPNT-difference, was observed, but not for the head-to-neutral test. It can be concluded that specific aspect of neck kinesthetic functions (i.e., movement sense) importantly contributes towards oculomotor and balance control, which is more evident under neck torsion positions in neck pain patients, but is less pronounced in asymptomatic individuals.
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Statistical determinants of visuomotor adaptation along different dimensions during naturalistic 3D reaches. Sci Rep 2022; 12:10198. [PMID: 35715529 PMCID: PMC9205902 DOI: 10.1038/s41598-022-13866-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 05/30/2022] [Indexed: 12/03/2022] Open
Abstract
Neurorehabilitation in patients suffering from motor deficits relies on relearning or re-adapting motor skills. Yet our understanding of motor learning is based mostly on results from one or two-dimensional experimental paradigms with highly confined movements. Since everyday movements are conducted in three-dimensional space, it is important to further our understanding about the effect that gravitational forces or perceptual anisotropy might or might not have on motor learning along all different dimensions relative to the body. Here we test how well existing concepts of motor learning generalize to movements in 3D. We ask how a subject’s variability in movement planning and sensory perception influences motor adaptation along three different body axes. To extract variability and relate it to adaptation rate, we employed a novel hierarchical two-state space model using Bayesian modeling via Hamiltonian Monte Carlo procedures. Our results show that differences in adaptation rate occur between the coronal, sagittal and horizontal planes and can be explained by the Kalman gain, i.e., a statistically optimal solution integrating planning and sensory information weighted by the inverse of their variability. This indicates that optimal integration theory for error correction holds for 3D movements and explains adaptation rate variation between movements in different planes.
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Sport-Specific Habitual Adaptations in Neck Kinesthetic Functions Are Related to Balance Controlling Mechanisms. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10248965] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Whilst the importance of trunk, lower and upper extremities for the efficiency of maintaining body sway is well documented, the effects of cervical spine function have been seldom investigated. Afferent information from high density proprioceptors located in the cervical spine can alter postural balance, however the effects of sport’s specific habitual adaptation on balance performance have not yet been investigated. Twenty-seven taekwondo fighters and thirty controls performed unilateral balance tasks while facing forward and during neck torsion balance test while standing on the force plate. Neck kinesthesia was measured with the Head-to-Neutral Relocation test and the Butterfly test with motion-inertial unit. Differences between balance tasks were analyzed using two-way ANOVA. Additionally, correlations between body sway parameters and neck kinesthesia were studied using Pearson correlation coefficient. No differences were found between forward facing and neck torsion balance tasks in taekwondo fighters. However, correlations were found between balance on the non-preferred leg and neck kinesthesia. On the contrary, healthy individuals presented with statistically significant differences between both balance tasks and correlations between balance and neck kinesthesia. Taekwondo fighters seem to present with habitual adaptations in balance control, that differ from non-trained individuals.
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Herter TM, Scott SH, Dukelow SP. Vision does not always help stroke survivors compensate for impaired limb position sense. J Neuroeng Rehabil 2019; 16:129. [PMID: 31666135 PMCID: PMC6822422 DOI: 10.1186/s12984-019-0596-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Accepted: 09/20/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Position sense is commonly impaired after stroke. Traditional rehabilitation methods instruct patients to visualize their limbs to compensate for impaired position sense. OBJECTIVE Our goal was to evaluate how the use of vision influences impaired position sense. METHODS We examined 177 stroke survivors, an average of 12.7 days (+/- 10 days (SD)) post-stroke, and 133 neurologically-intact controls with a robotic assessment of position sense. The robot positioned one limb (affected) and subjects attempted to mirror-match the position using the opposite limb (unaffected). Subjects completed the test without, then with vision of their limbs. We examined three measures of position sense: variability (Var), contraction/expansion (C/E) and systematic shift (Shift). We classified stroke survivors as having full compensation if they performed the robotic task abnormally without vision but corrected performance within the range of normal with vision. Stroke survivors were deemed to have partial compensation if they performed the task outside the range of normal without and with vision, but improved significantly with vision. Those with absent compensation performed the task abnormally in both conditions and did not improve with vision. RESULTS Many stroke survivors demonstrated impaired position sense with vision occluded [Var: 116 (66%), C/E: 91 (51%), Shift: 52 (29%)]. Of those stroke survivors with impaired position sense, some exhibited full compensation with vision [Var: 23 (20%), C/E: 42 (46%), Shift: 32 (62%)], others showed partial compensation [Var: 37 (32%), C/E: 8 (9%), Shift: 3 (6%)] and many displayed absent compensation (Var: 56 (48%), C/E: 41 (45%), Shift: 17 (33%)]. Stroke survivors with an affected left arm, visuospatial neglect and/or visual field defects were less likely to compensate for impaired position sense using vision. CONCLUSIONS Our results indicate that vision does not help many stroke survivors compensate for impaired position sense, at least within the current paradigm. This contrasts with historical reports that vision helps compensate for proprioceptive loss following neurologic injuries.
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Affiliation(s)
- Troy M Herter
- Department of Exercise Science, University of South Carolina, Columbia, SC, USA
| | - Stephen H Scott
- Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada
- Department of Anatomy and Cell Biology, Queen's University, Kingston, Ontario, Canada
- School of Medicine, Queen's University, Kingston, Ontario, Canada
| | - Sean P Dukelow
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.
- Department of Clinical Neurosciences, University of Calgary, 1403 29th St NW, Foothills Medical Centre, South Tower-Room 905, Calgary, AB, T2N2T9, Canada.
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Lefrançois C, Messier J. Adaptation and spatial generalization to a triaxial visuomotor perturbation in a virtual reality environment. Exp Brain Res 2019; 237:793-803. [PMID: 30607472 DOI: 10.1007/s00221-018-05462-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 12/21/2018] [Indexed: 11/29/2022]
Abstract
We explored visuomotor adaptation and spatial generalization of three-dimensional reaching movements performed in a virtual reality environment. We used a multiphase learning paradigm. First, subjects performed reaching movements to six targets without visual feedback (VF) (pre-exposure phase). Next, participants aimed at one target with veridical VF (baseline phase). Immediately after, they were required to adapt their movements to a triaxial visuomotor perturbation (horizontal, vertical, and sagittal translations) between actual hand motion and VF of hand motion in the virtual environment (learning phase). Finally, subjects aimed at the same targets as in the baseline (aftereffect) and pre-exposure phases (generalization) without VF (post-exposure phase). The results revealed spatial axis-dependent visuomotor adaptation capacities. First, subjects showed smaller intertrial variability along the horizontal compared to the sagittal and vertical axes during the baseline and learning phases. Second, although subjects were unaware of the visual distortion, they adapted their movements to each component of the triaxial perturbation. However, they showed reduced learning rate and less persistent adaptation (aftereffect) along the vertical than the horizontal and sagittal axes. Similarly, subjects transferred the newly learned visuomotor association to untrained regions of the workspace, but their average level of generalization was smaller along the vertical than the horizontal and sagittal axes. Collectively, our results suggest that adapting three-dimensional movements to a visual distortion involves distinct processes according to the specific sensorimotor integration demands of moving along each spatial axis. This finding supports the idea that the brain employs a modular decomposition strategy to simplify complex multidimensional visuomotor tasks.
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Affiliation(s)
- Catherine Lefrançois
- École de kinésiologie et des sciences de l'activité physique, Faculté de médecine, Université de Montréal, 2100, boul. Édouard-Montpetit, bureau 8225, Montreal, QC, H3T 1J4, Canada
| | - Julie Messier
- École de kinésiologie et des sciences de l'activité physique, Faculté de médecine, Université de Montréal, 2100, boul. Édouard-Montpetit, bureau 8225, Montreal, QC, H3T 1J4, Canada.
- Institut universitaire de gériatrie de Montréal, Université de Montréal, Montréal, QC, Canada.
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Klein J, Whitsell B, Artemiadis PK, Buneo CA. Perception of Arm Position in Three-Dimensional Space. Front Hum Neurosci 2018; 12:331. [PMID: 30186128 PMCID: PMC6110942 DOI: 10.3389/fnhum.2018.00331] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 07/26/2018] [Indexed: 12/02/2022] Open
Abstract
Proprioception refers to the senses of body position, movement, force and effort. Previous studies have demonstrated workspace and direction-dependent differences in arm proprioceptive sensitivity within the horizontal plane. In addition, studies of reaching in the vertical plane have shown that proprioception plays a key role in anticipating arm configuration dependent effects of gravity. This suggests that proprioceptive sensitivity could vary with the direction of arm displacement relative to the gravitational vector, as well as with arm configuration. To test these hypotheses, and to characterize proprioception more generally, we assessed the direction-dependence and arm postural-dependence of proprioceptive sensitivity in 3D space using a novel robotic paradigm. A subject’s right arm was coupled to a 7-df robot through a trough that stabilized the wrist and forearm, allowing for changes in configuration largely at the elbow and shoulder. Sensitivity was evaluated using a “same-different” task, where the subject’s hand was moved 1–4 cm away from an initial “test” position to a 2nd “judgment” position. The proportion of trials where subjects responded “different” when the positions were different (“hit rate”), and where they responded “different” when the positions were the same, (“false alarm rate”), were used to calculate d’, a measure of sensitivity derived from signal detection theory (SDT). Initially, a single initial arm posture was used and displacements were performed in six directions: upward, downward, forward, backward, leftward and rightward of the test position. In a follow-up experiment, data were obtained for four directions and two initial arm postures. As expected, sensitivity (d’) increased monotonically with distance for all six directions. Sensitivity also varied between directions, particularly at position differences of 2 and 3 cm. Overall, sensitivity reached near maximal values in this task at 2 cm for the leftward/rightward directions, 3 cm for upward/forward and 4 cm for the downward/backward directions. In addition, when data were grouped together for opposing directions, sensitivity showed a dependence upon arm posture. These data suggest arm proprioceptive sensitivity is both anisotropic in 3D space and configuration-dependent, which has important implications for sensorimotor control of the arm and human-robot interactions.
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Affiliation(s)
- Joshua Klein
- Interdisciplinary Graduate Program in Neuroscience, Arizona State University, Tempe, AZ, United States.,Alliance for Person-Centered Accessible Technologies, Arizona State University, Tempe, AZ, United States
| | - Bryan Whitsell
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, United States
| | - Panagiotis K Artemiadis
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, United States
| | - Christopher A Buneo
- Interdisciplinary Graduate Program in Neuroscience, Arizona State University, Tempe, AZ, United States.,Alliance for Person-Centered Accessible Technologies, Arizona State University, Tempe, AZ, United States.,School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, United States
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Toussaint L, Meugnot A, Badets A, Chesnet D, Proteau L. The specificity of practice hypothesis in goal-directed movements: visual dominance or proprioception neglect? PSYCHOLOGICAL RESEARCH 2016; 81:407-414. [PMID: 26873383 DOI: 10.1007/s00426-016-0748-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 01/28/2016] [Indexed: 10/22/2022]
Abstract
The study aimed to examine whether modifying the proprioceptive feedback usually associated with a specific movement would decrease the dominance of visual feedback and/or decrease, which appears to be the neglect of proprioceptive feedback in ensuring the accuracy of goal-directed movements. We used a leg positioning recall task and measured the recall error after 15 and 165 acquisition trials performed with both vision and proprioception or proprioception only, under either a normal or a modified proprioception condition (i.e., with a 1-kg load attached to the participants' ankle). Participant learning was evaluated in transfer with proprioception only. In support of the specificity of practice hypothesis, the recall errors in acquisition were significantly smaller when practice occurred with both vision and proprioception, in either the loaded or the unloaded leg condition, and they increased significantly in transfer when vision was withdrawn. An important finding of the study highlighted that withdrawing vision after 165 acquisition trials had less deleterious effects on the recall errors when practice occurred under the loaded leg condition. Under that modified condition, recall errors in transfer were similar when practice occurred with and without vision, whereas larger errors were observed following practice with vision under the normal proprioceptive condition. Overall, these results highlighted the dominance of vision in ensuring accurate leg positioning recall and revealed that the dominance of vision is such that the processing of proprioceptive feedback may be neglected. Importantly, modifying the proprioceptive feedback has the advantage of reducing what appears to be the neglect of proprioceptive information when movement execution occurs in a visuo-proprioceptive context. Practical considerations for rehabilitation are discussed at the end of the manuscript.
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Affiliation(s)
- Lucette Toussaint
- Université de Poitiers, Centre de Recherches sur la Cognition et l'Apprentissage, CeRCA, CNRS/UMR 7295, 5 rue Théodore Lefebvre, 86000, Poitiers, France.
| | - Aurore Meugnot
- Université de Poitiers, Centre de Recherches sur la Cognition et l'Apprentissage, CeRCA, CNRS/UMR 7295, 5 rue Théodore Lefebvre, 86000, Poitiers, France
| | - Arnaud Badets
- CNRS, Institut de Neurosciences Cognitives et Intégratives d'Aquitaine (UMR 5287), Université de Bordeaux, Bordeaux, France
| | - David Chesnet
- Maison des Sciences de l'Homme et de la Société (MSHS, USR 3565), Poitiers, France
| | - Luc Proteau
- Département de kinésiologie, Université de Montréal, Quebec, Canada
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Shi Y, Apker G, Buneo CA. Multimodal representation of limb endpoint position in the posterior parietal cortex. J Neurophysiol 2013; 109:2097-107. [DOI: 10.1152/jn.00223.2012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Understanding the neural representation of limb position is important for comprehending the control of limb movements and the maintenance of body schema, as well as for the development of neuroprosthetic systems designed to replace lost limb function. Multiple subcortical and cortical areas contribute to this representation, but its multimodal basis has largely been ignored. Regarding the parietal cortex, previous results suggest that visual information about arm position is not strongly represented in area 5, although these results were obtained under conditions in which animals were not using their arms to interact with objects in their environment, which could have affected the relative weighting of relevant sensory signals. Here we examined the multimodal basis of limb position in the superior parietal lobule (SPL) as monkeys reached to and actively maintained their arm position at multiple locations in a frontal plane. On half of the trials both visual and nonvisual feedback of the endpoint of the arm were available, while on the other trials visual feedback was withheld. Many neurons were tuned to arm position, while a smaller number were modulated by the presence/absence of visual feedback. Visual modulation generally took the form of a decrease in both firing rate and variability with limb vision and was associated with more accurate decoding of position at the population level under these conditions. These findings support a multimodal representation of limb endpoint position in the SPL but suggest that visual signals are relatively weakly represented in this area, and only at the population level.
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Affiliation(s)
- Ying Shi
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona
| | - Gregory Apker
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona
| | - Christopher A. Buneo
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona
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